Multiple access communications systems are common today. In such systems, multiple devices, e.g., wireless terminals, may have the ability to communicate with a base station at the same time. Multiple access communication systems are often implemented as cellular systems, where each cell normally corresponds to the coverage area of a single base station. Cells may include one or more different sectors. In sectorized cases, base stations often include different transmitters for different sectors. In addition, different sectors may use the same or different carrier frequencies.
Spread spectrum OFDM (orthogonal frequency division multiplexing) multiple access, is one example of a spectrally efficient wireless communications technology. OFDM can be used to provide wireless communication services. In OFDM spread spectrum system, the total spectral bandwidth is normally divided into a number of orthogonal tones, e.g. subcarrier frequencies. In a cellular network, the same bandwidth is often reused in all the cells of the system.
In various multiple access communications systems, there is a need to communicate transmitter information to wireless terminals, e.g., information indicating the carrier used by a particular transmitter, cell identification information, and/or sector identification information. While transmitting such information at extremely high power can increase the chance of detection of the transmitted information, it can lead to excessive and/or unnecessary interference, e.g., in cells or sectors several cells away from the transmitter. Dedicating huge amounts of power to transmitting transmitter information signals can also limit the amount of data that can be transmitted in a system since power allocated to transmitting the transmitter information signals may not be available for transmitting user data, e.g., text, video or speech data.
In view of the above discussion, it should be appreciated there is a need for methods and apparatus directed to the problem of communicating transmitter information in a reliable and easy to detect manner while limiting the amount of signal interference generated by signals used to transmit such information and also balancing the need to allocate power to such transmission with the importance of allocating power to the transmission of user data.